Water-tube boiler.



N0.'745,851. PATENTBD DEG. 1, 190s. J. P. HOTTMAN, SR. @L J. P. HOTTMAN,JR.

WATER TUBE BOILER.

APPLIOATION FILED 1320.13, 1902.

3 SHEETS-SHEET .1.

N0 MODEL.

i' '5 ifllilllllllllll/l/II,"

MUM/M.

A TTOHNE YS,

No. 745,851. PATBNTBD IDEC. 1,1903.

J. P. HOTTMAN, SR. & 1. F. .110112111111112l WATER TUB-E BOILER.

APPLIUATION FILED DBO. 1a, 1902.

3 SHEETS-SHEET 2.

N0 MODEL.

ooooooo 0 o o'o o 0 00000000 Wl TNE SSE S.'

A TTOHNE Y S.

110. 745,851. PATBNTBD 111:0. 1, 1903. J. 1. HOTTMAN, SB. & J. P.HOTTMAN, Jn.

WATER TUBE BOILER. APPLIUATION HIL-11D DB0. 13. 1903.

3 SHEETS-SHEET 3.

NO MODEL.

nllun w/TNESSES' A TTOHNE YS.

UNITED STATES 1ate11ted December 1,

PATENT OFFICE.

JOHN FERDINAND IIOTTMAN, SR., AND JOHN FERDlNAND HOTTMAN, JR., OFDUBUQUE, IOWA.

WATER-TUBE BOlLER.

SPECIFICATION forming part of Letters Patent No. 745,851, dated December1, 1903.

Application led December 13,1902. Serial No. 135.045. (No model.)

'o all zctom t may concern:

Be it known that we, JOHN FERDINAND HOTTMAN, Sr., and JOHN FERDINANDHorr- MAN, Jr., citizens of the United States, and residents of Dubuque,in the county of Dubuque and State of Iowa, have invented anew andImproved W'ater-Tube Boiler, of which the following is a full, clear,and exact description.

Our invention relates to improvements in water-tube boilers in which weaim to secure a vertical compact structure adapted to take up a limitedamount of space. XVe also seek to strengthen the internal construction,to resist the pressure without the employment of staybolts, andfurthermore,to provide means which enables us to use straight tubes forthe circulation of water in a way to increase the rapidity of watercirculation and rapidity in the generation of steam.

Further objects and advantages of the invention will be disclosed in thecourse of the subjoined description, and the novelty will be defined bythe annexed claims.

Reference is to be had to the accompanying drawings, forminga part ofthis specication, in which similar characters of reference indicatecorresponding parts in all the iigures.

Figure 1 is a vertical central section through a vertical water-tubeboiler constructed in accordance with our invention, the plane of thesection being indicated by the dotted line 1 1 of Fig. Fig. 2 is anothervertical sectional elevation taken in the plane of the dotted line 2 2of Fig. 3. Fig. 3 is a horizontal section on the line 3 8 of Fig. 1, andFig. a is a horizontal section through the fireboX in the plane of thedotted line 4.4 of Fig. l.

5 designates the outer shell or inclosing casing of our improvedvertical water-tube boiler, the same being of any suitable dimensionsand constructed in any desired way known to those skilled in the art,but preferably this outer shell is circular in cross-section, as shownby Figs. 3 and 4, thereby producing a structure which is of cylindricalform. At the lower end of the vertical cylindrical shell 5 is the bottomhead G, having a flange 7, which is united in any preferred or usual wayto the inclosing shell -a-S, for eX- ample, by rivets-and to this bottomhead is united the internal fire-boX, which is constructed as indicatedmore clearly by Figs. 1, 2, and 4i. Y

The substantially circular wall of this fireboX consists of a number ofcurved plates 8, which are placed in vertical positions and assembled inedgewise abutting relation, as shown by the drawings. Each verticalplateS is arched or curved transversely to a segment of a circle, andthe side edges of said vertical plate are fiangechas indicated at 9. Theseries or plurality of plates are assembled in abutting relation topresent the convex surfaces thereof to the internal-combustion chamber10 of the fire-box, while the concave surfaces of the plates are inopposing relation to the cylindrical casing or shell 5, as shown moreclearly by Fig. 4. The flanged edges 9 of each pair of curved plates 8are bent laterally, as at 11 in Fig. 2, and between the abutting anges 9of each pair of plates is interposed a reinforcing metallic bar or strip12. The length of the reinforcing bar or strip is not equal to theplates 8, and the end portions of ythis bar or strip are tapered orscarfed, as also shown more clearly byFig. 2. From this construction itwill appear that the bar or strip, with its scarfed ends, is interposedbetween the abutting flanges of two adjacent plates in a way to permitthe iianges to have abutting engagement at the upper and lower ends I ofsaid plates, whereby the top and bottom edges of the vertical plates maybe flanged horizontally, as at 13 14C in Figs. 1 and 2. The employmentof the reinforcement bars 01 strips 12 between the flanged edges of theplates and the use of a group of plates which are curved or archedinwardly produces a substantial construction of the iire-box,which isself-bracing or self-supporting, and thereby dispenses with theemployment of stay-plates or any other form of stays that are usuallyemployed in the construction of steam-boilers.

The fia-nge 13 at thelower edge of the arched plates forming thefire-box rests upon the lower head (i and may be united thereto in asubstantial Way-as, for example, by riveting the parts together.

The lower head 6 is united to the surrounding'shell 5 by a series ofstays 15, the end portions of which are fastened to the shell` IOO andto the head, respectively, in any suitable way.

Above the fire-box and within the cylindrical shell 5 we employ an innershell adapted to support a plurality of water-circulating tubes whichare disposed in inclined positions to facilitate the circulation of thewater, and said tubes extend across the internal shell to lie in thepath of the flame and escaping products of combustion which pass fromthe fire-box into and through the inner shell. This inner shell consistsof front and rear flue-sheets 16 17 a group of curved plates 18 at oneside, and a similar group of curved plates 19 at the other side, saidflue-sheets and the curved plates being united together in a substantialway to produce the internal shell, which is adapted to rest upon thefirebox formed by the series of curved plates 8 heretofore described.The flue-sheets 16 17 are disposed in vertical parallel positions and ata suitable distance one from the other, and these sheets are peculiarlyfashioned to enable us to use a plurality of water-tubes, which areessentially disposed in rows and in inclined positions. The peculiarityin the construction of each liuc-sheet 16 or 17 resides in bending thesheet at regular frequent intervals to produce the inclined members 20,each of these members extending the full width of the flue-sheet anddisposed in a plane inclined to the vertical plane of the sheet proper,each inclined member 2O lying between offsets or shoulders 21. Itis tobe understood that the offsets or shoulders are bent in the fine-sheetat regular intervals to produce the inclined members 20, and thefluesheets 16 17 are disposed in the opposing relation shown by Fig. l,so as tobring the inclined members 2O at different elevations and atright angles to the plurality of tubes The peculiar construction of theoffset fluesheets with the inclined members enables us to use straightwater-tubes 22, which have their end portions extended through themembers and expanded therein or otherwise united thereto. These straightwater-tubes 22 are arranged in rows, as shown by Figs. 1 and 2, each rowbeing inclined upwardly from the flue-sheet 16 toward the flue-sheet 17,a plurality of these rows of tubes being used throughout the depth ofthe internal shell, whereby the lowermost row of tubes lies immediatelyabove the combustion-chamber 10 and the uppermost row of tubes visimmediately below the crown-sheet 23. The series of vertical plates 1819 are assembled in abutting relation, each sheet of the series beingdisposed in a vertical position and each sheet being furthermore curvedor arched transversely in the Ysegment of a circle. Furthermore, eachsheet of the series 18 19 is flanged at its side edges, as at 24, andthe adjacent sheets are disposed in abutting relation, except thatprovision is made for the reception between the lianges 24: of thereinforcementbars 25, the latter having their ends beveled or scarfedand terminating within the upper and lower edges of the sheets in asimilar way to the arrangement of the reinforcement-bars 12 as to theplates 8 of the fire-box heretofore described.

The arched plates forming the series 18 19 are disposed to present theirconvex surfaces to the products of combustion which circulate within theinternal shell, while the concave surfaces of the series of plates 18 19are presented in opposing relation to the cylindrical casing 5. Theemployment of the curved plates and the reinforcement-bars produces aninternal shell which is self-supporting and of the necessary internalstrength to withstand the pressure within the boiler without resortingto the employment of stay-plates or other means to secure said internalshell within the inclosing casing. The vertical reinforcement-bars 25terminate short of the upper and lower edges of the plates 18 19, sothat the anges at the end portions of the plates will be brought intoabutting relation, and the internal shell is thereby adapted to beflanged at its bottom, as at 26, and at its top, as at 27. The flange 26at the bottom of the internal shell registers with the iiange 11 at thetop of the lire-box, so that the shell and the fire-box may be united ina substantial way, as by riveting the parts. The crownsheet 23 isadapted to rest on the flange 27 at the upper end of the internal shell,and these parts may also be riveted or otherwise secured. Thecrown-sheet is furthermore provided with an upstanding central liange28, to which is riveted the lower end of a smokepipe 29, adapted to passthrough the steamdome of the boiler and through the upper head 30, saidhead being flanged, as at 31, and riveted within and to the upper end ofthe cylindrical casing 5. This upper head, as is usual in the art, isstayed by the employment of the braces 32, which have their oppositeends fastened to the shell 5 and to the head 30. (See Figs. 1 and 2.)

The fine-sheet 16, at the upper end thereof, above the uppermost row oftubes 22, is reinforced by the stay-bars 33, which are fastened to thestraight portion of the fine-sheet by stay-bolts in a way well known tothose skilled in the art. In a similar way the lower straight portion ofthe fine-sheet 17 below the lowermost row of tubes 22, is reinforced bya series of stay-bars 34, which are also fastened to the flue-sheet bystay-bolts. The fire-box and the internal shell are disposed within theboiler to provide a water-space 35, which surrounds the joints betweenthe several parts and iiows over the'crown-sheet 23, so as to partlysurround the smoke-pipe 29, and in this water-chamber 35 is arranged adiaphragm 36. This diaphragm is disposed adjacent and parallel to theoffset flue-sheet 17 and it extends from the fire-box to the upper endof the internal shell. This diaphragm IOO IIO

*massi 3 may be secured in place within the boiler in any preferred way,and by disposing it quite close to the flue-sheet I7 the water-spacebetween the diaphragm and the flue-sheet is made quite narrow, thusforming an uptake for a rising column of steam and water at the upperend of the tubes and promoting the rapid circulation of water throughthe plurality of inclined tubes.

Our improved boiler is self-contained-that is to say, all the parts areassembled and united into one integral structure, so that the boiler canbe set up in a short space of time or be moved from place to placewithout the inconvenience following the use of other types ofsteam-boilers. There are no rivets or joints exposed to the action ofthe ire, and we are able to use a single thickness of steel which isexposed to the fire, thus permitting the employment of a comparativelyheavy grade of steel in the manufacture of the structure. By using steelsheets of greater thickness than can ordinarily be employed we are ableto maintain a high steam-pressure, and the strength and durability ofthe boiler are materially promoted. The products of combustion passthrough the smoke-pipe and through the steam-dome, thus superheating thesteam, which is of great advantage in the operation of expansive-enginesemployed in land and marine practice. The arrangement of the internalparts of the boiler secures a free and unobstructed passage for thecirculation of the water, thereby lessening the deposit of scale. Thewater-tubes serve to brace and stay the flue-sheets, and the circulationis increased by the use of straight tubes and by arranging these tubesin inclined positions.

rllhe boiler can be used as an internallyfired boiler by placingfire-doors in convenient points in the lower fire-box, or it can befired by the use of the Dutch oven-furnace or by any of the differentstyles of mechanical stoker-furnaces now on the market. The constructionof the boiler insures a large water-supply and a rapid generation of thesteam, thus maintaining a constant delivery of' steam and a steadyuniform water-line.

Having thus described our invention, we claim as new and desire tosecure by Letters Patent- I. In a steam-boiler, a fire-box consisting ofa plurality of vertically-ranging plates, each curved on a given radius,said plates be'- ing assembled to bring their concave surfaces inopposing relation to a surrounding waterspace and with their convexsurfaces forming the boundary of the combustion-chamber.

In a steam-boiler, a fire-box consisting of a plurality of flangedcurved plates assembled for their flanges to have abutting engagement,and stay-bars provided with reduced ends and secured between the flangesof the plates, each stay-barbein g shorter than the plates.

In a steam-boiler, a lire-box having a plurality of vertically-rangingcurved plates assembled in abutting relation along their vertical edgesand provided with vertical flanges, and a series of interposedreinforcement-bars secured between the flanges of said plates.

l. In a steam-boiler, a fire-box having a plurality of arched or curvedplates having flanges, and a series of reinforcement-bars provided withtapered ends and secured to and between Ithe flanges of the adjacentplates. p

5. In a water-tube boiler, an internal shell consisting of a series ofvertical plates arched transversely, and opposing liuc-sheets united tothe arched plates and provided with a series of inclined offsets,combined with straight tubes secured in the offsets of said flue-sheetsand disposed in corresponding inclined positions across the internalshell.

6. In a water-tube boiler, an internal shell consisting of flue sheets,and a series of curved plates all assembled in a substantial relation,combined with an external shell, and rows of inclined water-tubessecured in the flue-sheets of said internal shell.

7. In a water-tube boiler, an internal shell consisting of parallelflue-sheets, and two series of curved plates disposed in abuttingrelation and united to the flue-sheets, combined with a lire-box towhich the internal shell is united, an external shell inclosing theinternal shell and the fire-box, a series of tubes secured in theflue-sheets of the internal shell, and a crown-sheet fastened to theinternal shell. l

S. In a water-tube boiler, an internal shell having offset members inopposing relation, a series of vertically-ranging members between theoffset members, said verticallyranging members being curved transverselyand assembled in abutting relation along their vertical edges, andreinforcement strips or bars secured to and between the abutting edgesof adjacent members, combined with an external shell, and a series oftubes supported by the offset members within the internal shell.

9. In a water-tube boiler, an internal shell consisting of paralleloffset flue-sheets, and curved or arched plates united in series to thefluesheets, combined with an external shell, and straight inclined tubessecured between the offset portions of the flue-sheets.

lO. In a water-tube boiler, the combination of a fire-box, au internalshell secured to said fire-box and having opposing line-sheets providedwith inclined offsets, straight inclined tubes secured in the offsets ofsaid flue-sheets and disposed within said internal shell, all of saidtubes being inclined in one direction, an external shell, and adiaphragm secured between the external and internal shells and disposedin close relation to the flue-sheet to which is secured the elevatedends of the correspondingly-inclined tubes.

11. In a water-tube boiler, the combination IOO IIO

Inv testimony whereof we have signed our xo of e fire-box, an internalshell having offset names to this specification in the presence offlue-sheets provided with straight upper and lower portions, stayssecured to said straight two subscribing' witnesses. portions of thefine-sheets at the upper and lower ends thereof, a series of straighttubes secured to the Hue-sheets between the offset portions thereof, anexternal shell, a erownsheet secured to the internal shell, and asmoke-pipe leading from said crown-sheet.

JOHN FERDINAND HOTTMAN, SR. l JOHN FERDINAND HOT'IMAN, JR.

Witnesses:

J oHN P. SCHROEDER, C. B. SCHERR.

